1. Field of the Invention
The present invention relates to a packet communication device, a packet communication method, and a recording medium on which a packet communication program is recorded, and particularly, a packet communication device which autonomously set an operation mode, a packet communication method, and a packet communication program.
This application is based upon and claims the benefit of priority from Japanese patent application No. 2007-005863, filed on Jan. 15, 2007, the disclosure of which is incorporated herein in its entirety by reference.
2. Description of Related Art
A packet communication device of this type is connected to buses, selects an appropriate operation mode of the device according to a connection environment to the outside, and operates to conform an operation of the device to the connection environment. An example of the packet communication device is described in Japanese Patent Application Laid-Open No. 2000-66992 (JP-A 2000-66992). The packet communication device is shown in FIG. 7.
A packet communication device 73 described in JP-A 2000-66992 shown in FIG. 7 sets a connection between structural units inside a device in accordance with a connection environment to the outside. In this case, the connection environment corresponds to case in which a primary side and a secondary side are set to two external buses connected by the packet communication device 73 and the primary interface and the secondary interface must be connected to the primary external bus and the secondary external bus, respectively. The packet communication device 73 includes a connection control unit 731, a primary interface 732, a secondary interface 733, a connection control unit 734, and an operation mode control unit 735. The connection control unit 731 is connected an external bus 71 and switches connection paths to an internal block depending on whether the external bus 71 is on the primary side or the secondary side. The connection control unit 734 is connected an external bus 74 and switches connection paths to the internal block depending on whether the external bus 74 to be connected is on the primary side or the secondary side. The primary interface 732 is connected to the primary external bus and the secondary interface 733 is connected to the secondary external bus. The operation mode control unit 735 controls a connection between the connection control unit 731 and the connection control unit 734 by a designation of the control bus 72.
The operation mode control unit 735 receives a control signal from the control bus 72. The control signal notifies that the external bus 71 or the external bus 74 is the primary bus. By using the information, the connection control unit 731 is connected to one of the primary interface 732 and the secondary interface 733, and the connection control unit 734 is connected to the other of primary interface 733 and secondary interface 732. According to this setting, the primary interface 732 is connected to the primary bus, and the secondary interface 733 is connected to the secondary bus.
A first disadvantage of the packet communication device is that a system administrator or management software must set an appropriate operation mode of the packet communication device according to connection environment to the outside of the device.
A second disadvantage of the packet communication device is that a physical device or dedicated software to set an operation mode of a packet communication device is necessary.